Platform assembly for a crane



p 5, 1967 A.v H. WILKINSON 3,339,669

I PLATFORM.ASSEMBLY FOR A CRANE Filed June 2, 1966 4 Sheets-Sheet 1 INVENTOR. A/v/fl H Wf/k/njon BY a 2 #3 QMJM A TTORNEY Sept. 5, 1967 A. H. 'WlLKlNSON 3,339,669

I PLATFORM ASSEMBLY FOR A CRANE 4 Sheets-Sheet 2 Filed June 2, 1966 ms i 50 108 A26 54 52 /04 7:4 j/ //a% l///2 m2 m6 INVENTOR.

I) A/v/n h. VV/Vk/hJOn E5. 10 BY A TTORNEY p 5, 1 A. H. WILKINSON 3,339,669

PLATFORM ASSEMBLY FOR A CRANE Filed June 2, 1966 4 Sheets-Sheet C5 mgfs Ff a

INVENTOR. A/v/n H. W/7k/h50/7 BY v A TTORNEY WILKINSON 3,339,669

PLATFORM ASSEMBLY FOR A CRANE Sept. 5, 1967 Filed June 2, 1966 4 Sheets-Sheet 4 ATTORNEY United Stats This invention relates to a platform assembly for a crane and more particularly to a horizontally elongated platform which can be attached to a crane and which is movable in a generally universal manner in different horizontal and vertical positions as well as different inclinations.

There is a present need for a platform unit to be used in conjunction with the cleaning, painting or repairing of elongated highway signs or the like which are suspended or mounted above the ground. The prior art shows the use of buckets or the like which are supported on the upper ends of booms. However, these buckets have a limited amount of space providing a limited degree of movement and are difiicult to maneuver properly in connection with the cleaning, painting or repairing of signs or the like having any substantial horizontal dimensions. It is also understood that the prior art shows the use of platforms, generally of quite limited horizontal dimensions; however such platforms are not maneuverable in the manner of the present invention as will hereinafter appear.

The crane to which the platform assembly of the present invention is applied will have a longitudinally extensible boom including an inner boom section connected to the crane and an outer boom section slidably connected to the inner boom section. The connection between the two boom sections will generally be telescopic but this invention is not necessarily limited thereto; however the outer boom will be movable longitudinally outwardly and inwardly with respect to the inner boom section. The inner boom section will be pivotally connected to the crane and means will be provided for moving the boom about the pivot connection to different angles of inclination. Additional power means will be provided to move the outer boom section inwardly and outwardly with respect to the inner boom section. A hook or other material-engaging means will be attached to the end of a cable passing downwardly from a sheave at the outer end of the outer boom section; the other end of the cable will be wound around a winch on the crane or other suitable means capable of winding or unwinding the cable so as to move the hook upwardly or downwardly with respect to the outer end of the outer boom section. Preferably, the boom will be pivotally mounted on a supporting structure which will provide a rotary movement with respect to the vehicle upon which the crane is mounted. The present invention includes a platform assembly of considerable longitudinal extent which has one end pivotally connected to the boom; the opposite end of the platform assembly is adapted to be connected to the hook. The pivotal end of the platform unit is slidable with respect to the boom itself such that the inner pivotal end of the platform will move inwardly and outwardly (or downwardly and upwardly) with respect to the inner boom section in conjunction with the inward and outward movement of the outer boom section. Naturally, the winding or unwinding of the cable upon which the hook is mounted will have to be coordinated with the movement of the outer boom section to maintain the platform in a substantially horizontal position; as a corollary to this, the inclination of the platform assembly can be varied by moving the hook and cable.

In a preferred embodiment of the present invention the outer boom section is mounted telescopically within the inner boom section and a track is mounted along the atent 3,339,669 Patented Sept. 5, 1967 'ice length of the lower boom section. A slidable shoe or carriage is mounted on a track and a cable of fixed length iS attached at one end to the slidable carriage and at its other end to a fixed point on the outer boom section. The pivotal end of the platform assembly, therefore, is pivotally connected to the slidable carriage while the opposite end of the platform assembly is connected to the hook. With this arrangement, as the outer boom is moved telescopically outwardly with respect to the inner boom section the cable of fixed length will pull the slidable carriage and, hence, the platform assembly itself upwardly (or outwardly) along the track. Simultaneous adjust ment of the cable and hook will place the platform assembly in the proper horizontal position.

When it is desired to use the hook (or equivalent material-engaging means) for lifting or handling articles other than the platform assembly itself it is possible to disengage the platform assembly by removing the pivotal attachment to the carriage or, in accordance with another feature of the present invention, to attach the outer end of the platform assembly to the outer end of the inner boom section whereby the platform assembly will move essentially integrally with the inner boom section.

Therefore, it is a principal object of the present invention to provide a platform assembly of the type described herein which is pivotally attached at one end to the boom and which is connected at its opposite end to the conventional hook which is supported from the upper end of the boom; the foregoing pivotal connection is associated with the boom structure such that the former will move outwardly and inwardly (upwardly and downwardly) in conjunction with the outward and inward movement of the outer boom section.

It is a further object of the present invention to provide a platform assembly of the type described herein wherein the pivotal and sliding connection includes a track mounted along the length of the lower boom section and a slidable shoe or carriage which is slidable along the track and which is pivotally connected to the pivotal end of the platform assembly and wherein a cable of fixed length is attached at one end to the outer boom section and at its other end to the slidable carriage.

A further object of the present invention is to provide a platform assembly of the type described herein wherein the outer end of the platform assembly is also attachable to the outer end of the inner boom section.

Other and further objects and advantageous features of the present invention will hereinafter more fully appear in connection with a detailed description of the drawings in which:

FIGURE 1 is a side elevation of a vehicle showing the telescopic boom in a retracted position with the platform assembly resting upon its support;

FIGURE 2 is a view similar to FIGURE 1, on a smaller scale, showing the boom in an elevated and extended condition with the platform unit suspended in a horizontal position between the hook and the upper end of the lower boom section;

FIGURE 3 is a side elevation of the boom'and platform assembly by themselves;

FIGURE 4 is a bottom view of the track and lower boom section;

FIGURE 5 is a side elevation of the track and lower boom section;

FIGURE 6 is a sectional view of the track taken along section line 66 of FIGURE 4;

FIGURE 7 is a sectional view of the track taken along section line 77 of FIGURE 4;

FIGURE 8 is a side elevation of the slidable carriage or shoe;

FIGURE 9 is an end View of the slidable carriage 3 shown in FIGURE 8 also showing its relation to the track and lower boom section;

FIGURE 10 is a fragmentary end view showing the attachment of the platform to the upper end of the lower boom section;

FIGURE 11 is a fragmentary side elevation showing the attachment of the outer end of the platform to the upper end of the lower boom section; and

FIGURE 12 is a fragmentary side elevation showing the details of the platform latch which permits the attachment shown in FIGURES 10 and 11.

Referring to the drawings in detail, FIGURE 1 shows a truck or similar vehicle generally designated by the reference character 10 upon which is mounted a crane generally designated by the reference character 12. The crane includes a boom 14 comprising a lower (or inner) boom section 16 and an upper (or outer) boom section 18 which is telescopically received within the lower boom section 16. The details of the telescopic connection are not shown. However it should be understood that suitable guides and/or rollers (not shown) are mounted within the lower boom section 16 to facilitate the sliding or telescopic movement of the outer boom section 18. The outer boom section 18 is preferablyuniform throug out its cross section, generally rectangular; the lower boom section 16 is preferably tapered with the large end of the taper being adjacent a support 20. The lower end of the lower boom section 16 is pivotally attached to the support 20 (which can be conveniently referred to as a turret) by means of a pivotal connection 22. The support or turret 20 contains all of the necessary power equipment such as winches, etc. (not shown), for elevating the boom, for extending the upper boom section 18, for adjusting the position of the hook, and for revolving the turret about a vertical axis.

An auxiliary boom 24 having a lower boom section 26 and an upper boom section 28 is provided for the purpose of lowering and raising the main boom 14. The upper end of the auxiliary boom 24 is pivotally attached by means of the pivotal connection 30 to the main boom 14 adjacent the upper end of the lower boom section 16. The lower end of the lower boom section 26 of the auxiliary boom 24 is pivotally attached to the supporting structure 20 by means of the pivotal connection 32. Any means can be employed to move the boom section 28 inwardly and outwardly with respect to the boom section 26 of the auxiliary boom 24; for example, it is possible to use the ball screw drive shown in Patent No. 3,171,296, issued Mar. 2, 1965, with the latter drive preferably being powered by a suitable electric motor (not shown).

Any suitable means can be employed for moving the outer boom section 18 telescopically outwardly with respect to the inner boom 16; the details of such a moving means are not considered essential to an understanding of the present invention and, hence, will be only briefly described. A cable 34 extends outwardly from the turret 20 to a point adjacent the upper end of the lower boom section 16. The inner or lower end of the cable 34 is preferably mounted on a winch (not shown) which can be powered by a suitable electric motor (not shown). The upper end of the cable 34 preferably passes around a sheave (not shown) mounted on the upper end of the lower boom section 16, thereafter around another sheave (not shown) mounted on the lower end of the upper boom section 18 and then is anchored to the upper end of the lower boom section 16; pulling (or winding in) the cable 34 will cause the upper boom section 18 to be urged telescopically outwardly with respect to the lower boom section 16; conversely releasing the tension on the cable 34, or unwinding this cable, will cause the boom section 18 to retract telescopically inwardly into the lower boom section 16. Another cable 36 extends outwardly from the turret 20 to the upper end of the boom section 18. The inner or lower end of this cable 36 is also wound on another winch (not shown) which may be powered by a suitable and separate electric motor (not shown). The upper end of the cable 36 passes around a sheave or pulley 38 mounted in the upper end of the upper boom section 18 downwardly around another sheave 40 in a small traveling block 42 and thence upwardly to an anchor point 44 at the upper end of the upper boom section 18. A hook 46 is attached to the lower end of the traveling block 42.

Purely by way of example, the turret 20 is shown as mounted near the forward end of the truck 10; naturally, suitable outriggers (not shown) will be employed at suitable places on the sides (or rear or front) of the truck to prevent the truck from tipping when the crane is lifting heavy loads. Of course, the turret 20 could be located adjacent the rear of the truck 10 with suitable outriggers (not shown) being employed in connection with the truck for the purpose of stabilizing the load. A11 upright support 48 is provided adjacent the rear of the truck such that the boom can rest against this support when not in use. The above described structure can be considered essentially conventional as far as the present invention is concerned. As will hereinafter appear the present invention is concerned with a platform assembly which is attached to the above described structure.

Referring now to FIGURES 3 to 7 inclusive, a track 50 is secured to the underside of the lower boom section 16. The track 50 is constructed of two elongated pieces of angle iron 52 and 54 which are connected together by means of a plurality of shorter angle iron pieces all designated by the reference character '56. Adjacent the right hand end of the track 50 (as it appears in FIGURE 5) there are two cross pieces 58 and 60 which are inverted with respect to the remaining angle pieces 56. The angle pieces 58 and 60 are provided with aligned holes 62 for the purpose of holding the platform assembly against the lower boom section 16 in a manner later to be described. Adjacent the extreme right hand end of the track 50 as it appears in FIGURES 4 and 5, (see also FIGURE 7) a rod 64 passes through both of the angle members 52 and 54 adjacent the horizontal portions 66 and 68 of these angle members respectively. The outer ends of the rod 64 will provide an upper stop for the slidable carriage later to be described. Mounted on the rod 64 between the angle members 52 and 54 is a hollow pipe or tube 70 which is rotatable with respect to the rod 64. The purpose of the rotatable tube 70 is to prevent unwanted friction between the cable 36 and the end of the track 50 when the boom 14 is in a substantially vertical position with a load on the hook 46.

As shown on FIGURES 1, 2 and 3, but as best shown in FIGURES 8 and 9, a slidable carriage 72 is mounted on the track 50. The carriage 72 is of essentially rectangular construction, being made from side plates 74 and 76 and end plates 78 (only one of which is shown in FIG- URE 9) which are welded to the side plates 74 and 76 adjacent the opposite ends thereof. Suitable rollers, all designated by the reference character 80, are mounted within the carriage 72 preferably with four rollers at each end, with two rollers at each end bearing against the upper sides of the horizontal portion 66 and 68 of the angle members 52 and 54 and two rollers at each end bearing against the underside of these same horizontal portions. The rollers are mounted on the side members 74 and 76 by suitable bearings, nuts, etc., all generally designated by the reference character 82. At the forward end of the carriage 72 there is provided an eye 84 to which is secured the lower end of a cable 86 of fixed length. The upper end of the cable '86 is connected to the upper end of the upper boom section 18 by means of the connection 88.

A pivotal connection is provided midway between the ends of the carriage 72 for attachment to the platform as will hereinafter appear. This pivotal connection includes horizontal angle iron 90 which is welded to ears 92 and 94. The ear 92 is pivotally connected to the side plate 74 by means of the bolt 96. A similar connection (not shown) is provided to permit pivotal attachment between the car 94 and the side plate 76. Suitable holes 98 and 100 are provided in the angle member 90 to permit bolting to the end of the platform which will be described hereinafter.

The platform unit, generally designated by the reference character 102, included an elongated and substantially flat floor sction 104 which is suitably braced both longitudinally and transversely as desired. The left hand end (as it appears in FIGURE 3) of the plat-form 102 is bolted to the angle member 90 by the use of bolts (not shown) which pass through the holes 98 and 100 in the angle member 90 and through corresponding holes (not shown) in the platform 102. The right hand end (as it appears in FIGURE 3) of the platform 102 is provided with a vertical plate '106 which is welded or otherwise secured to the end of the platform and which projects somewhat above the floor 104. The upper projecting part of the plate 106 is provided with a hole 108 through which the hook 46 is adapted to pass to permit the connection shown in FIGURES 2 and 3. The sides of the platform 102 are provided with vertical railings 110 and 112 as a safety feature for any person standing on the platform 102.

The upright support 48 is connected to the bed of the truck by means of the inclined legs 114 and 116. The lower ends of the legs 114 and 116 can be attached to the truck bed by any suitable means; at their upper ends the legs 114 and 116 come together at a horizontal step 118 which also connects with the upright support 48. As best shown in FIGURE 1, the rear end of the platform 102 is adapted to rest on the horizontal step 118. At the same time, the boom is adapted to rest against the upper end of the vertical upright 48.

In the event that it is desired to connect the outer or rear end of the platform to the upper end of the inner boom section (as shown in FIGURES and 11), the platform latch of FIGURE 12 may be employed. In FIGURE 12 there is shown a horizontally extending latch 120 which is pivotally connected to the vertical upright 48 by means of pin 122. On the right hand side of the vertical upright 48 there is mounted (bywelding, etc.) a suitable rod 124 which serves as a stop for the latch when it is moved to the dotted line position shown in FIGURE 12. If, for example, the latch 120 is moved to the dotted line position shown in FIGURE 12 and the platform is subsequently lowered down on top of the latch it is possible, at such time, to disengage the hook 46 from the plate 106 and to continue lowering the boom 14 until the. plate 106 is received between the cross supports '58 and 60 on the track 50 as shown in FIGURES 10 and 11; this, of course, presumes that the outer boom section 18 has been moved to its innermost telescopic position in relation to the inner boom section 16. A pin 126 can be passed through the holes 62 of the cross members 58 and 60 and through the hole 108 of the vertical plate 106 so as to secure the platform in the position shown in FIGURE 11. If desired, a retaining means such as a cotter pin 128 can be used to hold the pin 126 in place.

Starting from the road position shown in FIGURE 1 the truck is, first of all, parked in the proper position in relation to the sign which is to be cleaned, painted, repaired, installed, removed, etc. The hook 46 is brought into engagement with the hole 108 in the plate 106 (actually the upright support 4 8 is bifurcated such that there is ready access to the plate 106). With the hook 46 engaged in the plate 106 and the cable 36 sufiiciently taut, the boom 14 can be raised by causing the outer portion 28 of the auxiliary boom 24 to be telescoped inwardly with respect to the inner boom section 26 of this auxiliary boom. When the platform 1% has cleared the upright support 48, it is then possible to move the platform outwardly by causing the outer boom section 18 of the main boom 14 to move telescopically outwardly with respect to the inner boom section 16; as the outer boom section 18 moves outwardly the cable 86 will force the shoe or carriage 72 to roll outwardly on the track 50 and to carry with it the platform 102. Naturally, it will be necessary to unwind the cable 36 in conjunction with the outward movement of the boom section 18 to retain the platform 102 in a substantially horizontal position. The same considerations hold true when the angle of the main boom 14 is changed. FIG- URE 2 shows the position of maximum outward movement of the platform 102. As mentioned previously, the ends of the rod 64 shown in FIGURE 7 will prevent outward movement of the carriage 72 beyond this location.

It can be seen from the above that the outward movement of the platform 102 is directly responsive to the outward movement of the outer boom section 18. The mounting of the track on the inner boom section 16 and the I extension of the cable 86 from the carriage 72 to a fixed point on the outer boom is occasioned by the fact that the outer boom section 18 is telescopically mounted within the inner boom section 16. However if the outer boom section 18 were itself mounted in a track below and along the inner boom section 16, the inner pivotal end of the platform 102 could be pivoted directly to the lower end of the outer boom section. It is also possible to design a telescoping boom arrangement where a longitudinal slot is provided along the length of the lower boom section so crane wishes to use the crane in an essentially oonvention-.

al manner without carrying the platform 102 on the lower boom section 16, it should be obvious that the platform 102 can be disconnected from the slidable carriage 72 by removing the pivotal connection 96 (the latter being either a bolt or a pin); if desired, an additional vertical standard (not shown) similar to the standard 48 can be employed adjacent the forward end of the truck 10 for supporting the forward end of the platform 102 when it has been disconnected completely from the boom structure.

Whereas the present invention has been described in particular relation to the drawings attached hereto, it should be understood that other and further modifications, apart from those shown and suggested herein, may be made within the spirit and scope of this invention.

What is claimed is:

1. A platform assembly for a crane of the type having a longitudinally extensible boom including an inner boom section connected to said crane and an outer boom section slidably connected to said inner boom section and movable longitudinally outwardly and inwardly with respect to said inner boom section, means for moving said outer boom section inwardly and outwardly with respect to said inner boom section, a cable extending from said crane to the outer end of said outer boom section, a hook means attached to the outer end of said cable adjacent said outer end of said outer boom section and means for moving said cable inwardly and outwardly with respect to said crane so as to move said hook upwardly and downwardly with respect to the outer end of said outer boom section, said platform assembly comprising a longitudinally extending platform having one end pivotally connected to said boom and its other end adapted to be connected to said hook means, said one end of said platform being slidably associated with said boom such that said one inner end of said platform moves inwardly and outwardly wrth respect to said inner boom section in conjunction with the inward and outward movement of said outer boom sectionj 2. The improvement according to claim 1 where said outer boom section is telescopically received within said inner boom section, wherein a track is mounted along the length of said inner boom section, wherein a slidable shoe is mounted for sliding movement along said track, wherein said one end of said platform unit is pivotally connected to said shoe and wherein a second cable of fixed length is attached at one end to said outer boom section and at its other end to said shoe.

8 3. The improvement according to claim 2 wherein the outer end of said platform assembly is also attachable to the outer end of said inner boom section.

10 REINALDO P. MACHADO, Primary Examiner. 

1. A PLATFORM ASSEMBLY FOR A CRANE OF THE TYPE HAVING A LONGITUDINALLY EXTENSIBLE BOOM INCLUDING AN INNER BOOM SECTION CONNECTED TO SAID CRANE AND AN OUTER BOOM SECTION SLIDABLY CONNECTED TO SAID INNER BOOM SECTION AND MOVABLE LONGITUDINALLY OUTWARDLY AND INWARDLY WITH RESPECT TO SAID INNER BOOM SECTION, MEANS FOR MOVING SAID OUTER BOOM SECTION INWARDLY AND OUTWARDLY WITH RESPECT TO SAID INNER BOOM SECTION, A CABLE EXTENDING FROM SAID CRANE TO THE OUTER END OF SAID OUTER BOOM SECTION, A HOOK MEANS ATTACHED TO THE OUTER END OF SAID CABLE ADJACENT SAID OUTER END OF SAID OUTER BOOM SECTION AND MEANS FOR MOVING SAID CABLE INWARDLY AND OUTWARDLY WITH RESPECT TO SAID CRANE SO AS TO MOVE SAID HOOK UPWARDLY AND DOWNWARDLY WITH RESPECT TO THE OUTER END OF SAID OUTER BOOM SECTION, SAID PLATFORM ASSEMBLY COMPRISING A LONGITUDINALLY EXTENDING PLATFORM HAVING ONE END PIVOTALLY CONNECTED TO SAID BOOM AND ITS OTHER END ADAPTED TO BE CONNECTED TO SAID HOOK MEANS, SAID ONE END OF SAID PLATFORM BEING SLIDABLY ASSOCIATED WITH SAID BOOM SUCH THAT SAID ONE INNER END OF SAID PLATFORM MOVES INWARDLY AND OUTWARDLY WITH RESPECT TO SAID INNER BOOM SECTION IN CONJUNCTION WITH THE INWARD AND OUTWARD MOVEMENT OF SAID OUTER BOOM SECTION. 